1. Field of the Invention
This invention relates to a caster brake control system and more particularly to a manually operable brake control system combined with a switch actuating mechanism, and in a specific embodiment with an unbalance sensing mechanism, for a portable washing apparatus. Means are provided to prevent operation of the machine unless the caster brake is engaged and the access door is closed.
2. Description of the Prior Art
A portable apparatus such as a washing machine, is subject to movement due to reaction torque during periods of braking, heavy agitation, or high speed spinning. It has been suggested in Haberstump U.S. Pat. No. 2,389,774 that a mechanism be provided by which feet are forced against the floor to raise the front casters from the floor and prevent the washing machine from moving. In Haberstump, there is no connection of the mechanism with the electrical control system of the washing machine.
In Michaud U.S. Pat. No. 2,783,055, a mechanical linkage is provided through which the machine can be lowered onto permanent legs once it has been rolled into position for washing.
Dupeux U.S. Pat. No. 3,356,384 describes a machine having three wheels. Two of these wheels operate as a pair and are mounted such that the wheel axes are at an obtuse angle with respect to each other. Also, at least one of the wheels is elliptical in shape. This combination prevents movement of the machine when subjected to the conditions of braking or high speed spinning.
Drews U.S. Pat. No. 3,635,491 teaches a foot-operated caster jack mechanism to raise the machine onto casters for moving and to lower the machine onto permanent mounting legs for stationary operation.
Weir et al U.S. Pat. No. 3,884,493 proposes four like casters with a first pair mounted substantially vertically and the second pair mounted at an angle to the vertical. Thus Weir proposes that the first pair will swivel and the second pair will not and that this nonswivelling action of the second pair will prevent movement while the machine is spinning and/or braking.
It is therefore apparent that various methods for solving the problem of machine movement during spinning or braking operations have been shown in the prior art. However, none of the known prior art has disclosed a brake control system which is incorporated into the electrical control system to render the apparatus inoperable unless the brake is activated and the access door is closed.